DE 100 57 759 A1 describes a rear roller blind for motor vehicles. This rear roller blind comprises a winding shaft that is rotatably supported underneath a rear window shelf, with one edge of a sheet-like shade being fixed on the winding shaft. The sheet-like shade is cut to an approximately trapezoidal shape at one edge and fixed to a pull-out rod at its other edge distant to the winding shaft. The pull-out rod is laterally guided in two guide rails that are either adhered to the inner side of the rear window or concealed in the car body behind the C-column panel. Elastically flexible thrust elements are guided in the guide rails in buckle-proof fashion.
The guide rails consist of an extruded aluminum profile with a continuous undercut groove. The groove is composed of a chamber of circular cross section and a groove slot that is narrower than the diameter of the chamber.
Sliding or guiding elements move in the guide rails, the sliding or guiding elements include a head, the cross section of which is adapted to the cross section of the circular chamber of the guide rail profile. This head has the shape of a ball or a short cylindrical section, dimensioned so that it cannot become jammed in the curved sections of the guide rails. The diameter of the neck also prevents the sliding elements from getting stuck in the slot of the guide groove.
The head of the guide element usually is an injection-molded plastic material.
Over time, the mating plastic guide element and aluminum rail is not rattle-free under all conditions. The friction contact between the plastic guide elements and the aluminum rail also is not optimal. In addition, certain difficulties must be overcome when installing the guide rails in the motor vehicle since the guide rails and the corresponding parts of the interior panel comprise separate components.